Experts think today's attacks may have been hastened by it as attackers may have feared the plans would be discovered during his interrogation.

Raffaello Pantucci, an international security expert for the Royal United Services Institute (RUSI), said the latest attacks are likely to lead to border controls between European countries being reimposed.

He said: "The reality is we have got a situation where there is a very large network of people in Belgium and France.

Eerie images of Brussels airport after terror attacks

The aftermath of the Brussels attacks; Several bombs went off at Brussels airport, another at a Metro station in Brussels and police search a top floor flat in Brussels for evidence all in pictures.

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REUTERS

Damage seen inside the departure terminal following the March 22, 2016 bombing at Zaventem Airport, in these photos made available to Reuters by the Belgian newspaper Het Nieuwsblad

“When Abdeslam gets arrested, you will have the network around him all starting to panic”

Raffaelo Pantucci of the RUSI

"When Abdeslam gets arrested, you will have the network around him all starting to panic.

"If you have problems building up, or people thinking about doing stuff, they might accelerate any planned attacks.

"If you have something you are thinking of doing, you will speed it up. Whereas before, you might have waited.

"You are concerned about what might get exposed and the last thing you want to do is get captured.

"It wouldn't surprise me if it was part of that network but we cannot know for sure."

Suicide bombers, including Abdeslam's brother Ibrahim, killed 130 people in Paris, and the terror cell had roots in Brussels suburb Molenbeek.

Attacks on airports usually suggest an international terrorism plot, as they are high profile targets which can undermine global security.

Mr Pantucci said: "At this point, there has not been a claim of responsibility.

Paris attacks: Suspect Salah Abdeslam shot & arrested

The most wanted IS memember Salah Abdeslam was shot and arrested in a counter terrorism raid in Brussels, said to be linked to last year's Paris attacks, in which 130 people died.

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Sky News

Paris attacks suspect Salah Abdeslam shot and arrested in Brussels

"An airport usually suggests international terrorism, but it would not surprise me if it was linked with the wider community around that network."

On the issue of airport security, he said: "Most airports you cannot get in without layers of security.

"They have long been targets and they are quite hard targets. The reality is, they are also high profile targets.

"If you can launch an attack there, you are striking at the international border and getting a lot of attention.